Active pulsation cancellation device for diesel particulate sampling systems

A particulate sampler is provided for conveying exhaust gas from exhaust gas source to analysis equipment. The particulate sampler includes a probe for receiving the exhaust gas and a transfer tube for conveying the exhaust gas from a tailpipe to a mixer. The mixer mixes the exhaust gas and a dilution gas from a dilution source. A dilution tunnel mixes and conveys the exhaust gas and dilution gas from the mixer to analysis equipment such as a filter or gas analyzers. A flow pulsation cancellation device includes an actuator in communication with at least one of the tailpipe, probe, transfer tube, mixer, and dilution tunnel for introducing a canceling pressure pulse to minimize the effects of pressures pulses present from the tailpipe within the sampler. The actuator may be a moveable membrane or a fluid flow control valve. Pressure sensors are used to measure the pressure of the undiluted and diluted exhaust gas, and a controller determines the desired canceling pressure pulse based upon the measured pressures.